Rabies Virus

The rabies virus is a neurotropic virus that causes rabies in humans and animals. Rabies transmission can occur through the saliva of animals and less commonly through contact with human saliva. The rabies virus has a cylindrical morphology and is the type species of the Lyssavirus genus of the Rhabdoviridae family. These viruses are enveloped and have a single stranded RNA genome with negative-sense. The genetic information is packaged as a ribonucleoprotein complex in which RNA is tightly bound by the viral nucleoprotein. The RNA genome of the virus encodes five genes whose order is highly conserved. These genes code for nucleoprotein (N), phosphoprotein (P), matrix protein (M), glycoprotein (G) and the viral RNA polymerase (L). The complete genome sequences range from 11,615 to 11,966 ht in length.

Scope and Importance:Rabies virus belongs to the order Mononegavirales, viruses with nonsegmented, negative-stranded RNA genomes. Within this group, viruses with a distinct "bullet" shape are classified in the Rhabdoviridae family, which includes at least three genera of animal viruses, Lyssavirus, Ephemerovirus, and Vesiculovirus. The genus Lyssavirus includes rabies virus, Lagos bat, Mokola virus, Duvenhage virus, European bat virus 1 & 2 and Australian bat virus. Rabies, one of the oldest and most feared zoonotic diseases known to mankind, is an acute, progressive, and almost fatal encephalomyelitis caused by the Rabies virus (RABV) and other Lyssavirus species of the family Rhabdoviridae. Despite the lack of accurate data on the global burden of neglected tropical diseases, the estimates of direct mortality due to rabies, transmitted most commonly through the bite of a rabid animal, are among the highest.

Market Analysis:
The annual number of human rabies deaths globally, in 2010, is estimated to be 61,000 (95% CI 37,000–86,000), with the vast majority of deaths (84%) occurring in rural areas. The estimated annual cost of rabies is US$ 6 billion (95% CI, 4.6–7.3 billion), with almost US$ 2 billion due to lost productivity after premature deaths and a further US$ 1.6 billion spent directly on post exposure prophylaxis. Most of the human deaths due to rabies occur in Asia and Africa. Estimates of human mortality due to endemic canine rabies in Asia and Africa annually exceed 30,000 and 23,000, respectively. In Latin America and the Caribbean, a substantial success in canine rabies control and a reduction in human rabies transmitted by dogs has been achieved during the past two decades. However, the incidence of bat rabies has reportedly increased, probably resulting in more human cases and livestock losses.Canine rabies has been eliminated from Western Europe, Canada, the United States of America (USA), Japan, Malaysia, and a few Latin American countries. Australia is free from carnivore rabies, and many Pacific Island nations have always been free from rabies and related viruses. In these areas, human deaths from rabies are restricted to people exposed while living or travelling in areas endemic for canine rabies. However, the cost of rabies prevention in many countries where wildlife rabies or bat rabies viruses circulate is substantial. About one to eight human rabies deaths occur annually in the USA as a result of wildlife rabies and an estimated US$ 300 million are spent per annum for rabies prevention.